Rotary blade pump



March 11, 1952 v o 2,588,430

ROTARY BLADE PUMP Filed Oct. 15,v 1945 4 SheetS-Sheetl IN V EN TOR.

March 1952 E. J. SVENSON 2,588,430.

INVENTOR. jaaaiflflwm March 11, 1952 E. J. SVENSON 2,588,430

ROTARY BLADE PUMP Filed Oct. 15, 1945 4 Sheets-Sheet 3 INVENTOR. flmzi/52 67550 March 11, 1952 E. J. SVENSON 2,588,430

ROTARY BLADE PUMP Filed Oct. 15, 1945 4 Sheets-Sheet 4 INVENTOR.

Patented Mar. 11, 195 2- ROTARY BLADE PUMP Ernest J. Svenson, Rockford,111;, assignor'to Odin Corporation, Chicago, 111., a corporation ofIllinois Application October 15, 1945, Serial No. 622,397

4 Claims.

This invention relates to pumping mechanisms, and particularly to pumpsof the rotary blade type.

Pumps of the rotary blade type have the advantage, when compared withplunger pumps, of providing a non-pulsating fluid delivery. Also, bladepumps generally provide a greater volumetric delivery for a given sizeand cost pumping installation. However, while blade pumps may be reliedupon to provide a pumping pressure equal to or greater than gear pumps,in conventional blade pumps difliculty is encountered in attempting toprovide fluid delivery at relatively high pumping pressures. Among thedifiiculties encountered are loss of mechanical and volumetricefficiency, undue wear, and jamming and freezing of the relativelymoving parts.

It is an object of the present invention to provide a rotary blade pumpof improved construction and improved operating characteristics.

More specifically stated, it is an object of the present invention toprovide a rotary blade pump which may be employed to deliver higherpumping pressures, with maintained mechanical and volumetric efiiciency,and with a minimum of wear, and without jamming or freezing ofthe parts.

Still more specifically stated, one of the objects of the presentinvention is to provide a rotary blade pump having an improvedarrangement of parts so as to maintain the stationary and rotarycooperating elements in balance, even when subjected to relatively highpumping pressures, whereby to eliminate distortion of the cooperatingparts and maintain mechanical and volumetric efiiciency, and minimizewear, as above set forth.

Further objects of the invention are to provide a pump structure of therotary blade type having an improved port and blade cooperation, animproved rotor and drive shaft arrangement, an improved cam structure,and an improved and balanced housing construction.

Various other objects, advantages and features of the invention will beapparent from the following specification when taken in connection withthe accompanying drawings wherein a preferred embodiment is set forthfor purposes of illustration.

In the drawings, wherein like reference numerals refer to like partsthroughout:

Fig. 1 is a general assembly view of a pumping structure constructed inaccordance with and embodying the principles of the invention, inassociation with its driving motor; 7

Fig. 2 is a longitudinalv sectional view of the pump structure of Fig.1, on an enlarged scale and taken as indicated by th line 2-2 of Fig. 4;

Fig. 3. is a transverse. sectional view of the pump, on the line 33 ofFig. 2;

Fig. 4 is a transverse sectional view of the pump on the line 44 of Fig.2;

Fig. 5 is a detail view of. the exhaust side plate, partly in section,and taken as. indicated by the line 5-5 of Fig. 3.;

Fig- 6' isan. exploded; perspective view of a number of the pump parts:

Fig. 6A. is a detail enlarged perspective view of one of the blades;

Fig. '7 is a partial and enlarged detail view showing the blade and camcooperation;

Fig. 8 is a. partial longitudinal sectional view of. the pump, taken asindicated by the broken line 88 of Fig. 4;

Fig. 9 is adetail view of the cam; and

Fig. 10 is an illustrative view showing the development of the camsurface.

The pump structure of the present invention may be utilized as apump ofgeneral utility, in various types of installations, and has particularapplicability to installations requiring non-pulsating delivery offluid, such for example as oil or the like, at high pressure andrelatively large volume.

Referring, more particularly to the drawings, in Fig. 1 an installationis illustrated comprising a rotary blade pump Ii], and its driving motorI2. The pump is adapted for suitable connection with an inlet supplypipe l4 leading from a source of fluid supply such as oil or the like,and with anoutlet pipe I6 adapted for connection with the machine ormechanism to be actuated, or other pressure connection. The pump may beconveniently supported by means of a frame bracket I8 forming a part ofa suitable frame structure.

It will be noted that the pump body is relatively small in respect tothe size ofthe driving motor l2, the high operating pressures of thepump requiring adriving motor of relatively larger power. 7

Referring to Fig. 2,. it will be seen that the pump comprises a mainbody .or housing 29 and an auxiliary housing or body 22 secured togetherby a series of annularly disposed studs or screws as indicated at 2t.The juncture between the housings is sealed by an annular gasket, asindicated at 2-6, com-pressed between the housings by the studs'24,whereby to provide a fluid-tight connection. The main housing or body isprovided with an annular flange 28 adapted to receive a series of studsor bolts 38 for securing the pump to the support plate I8 or othermember to which the pump is to be connected.

The inlet pipe I4 connects with a threaded opening 32 within the mainpump housing, this opening in turn communicating with an annular port orchannel 34 extending circumferentially within the main pump body. Asbest shown in Figs. 6 and 8, the annular channel 34 has communicatingtherewith two diametrically disposed inlet ports 36 and 38, of generallyarcuate cross section, and adapted for cooperation with the side plateand rotor structures, later to be described. Similarly the auxiliaryhousing body 22 is provided with a threaded opening 40 adapted forconnection with the exhaust pipe I6, and communicating with an annularchannel or passage 42 extending circumferentially of the auxiliaryhousing body. As shown in Figs. 2 and 6, the annular exhaust passage 42communicates with a pair of diametrically disposed exhaust ports 44 and46 of arcuate shaping similar to the shaping of the inlet ports 36 and38 of the main pump body. The exhaust ports 44 and 46 are displaced 90in respect to the positioning of the inlet ports 36 and 38, as will belater described.

Press-fitted into the main housing body is an inlet side plate 48 havinga radially extending flange portion 50 and an axially extending bushingor bearing portion 52. The flange portion 50 is provided with a pair ofinlet ports 54 and 58 co-mating with the inlet ports 36 and 38 of themain housing body.

Similarly there is provided an exhaust side plate 58 press-fitted intothe auxiliary pump body 22 having a radially extending flange portion 60and an axially extending bearing portion 62; the radially extendingflange portion being provided with a pair of arcuate exhaust ports 64and 66 co-mating with the exhaust ports 44 and 46 of the auxiliary pumpbody. In addition to the principal inlet and exhaust ports, the sideplates 48 and 58 are provided with certain additional ports andpassages, as will be later described.

A rotor 68 is rotatable between the side plates, the rotor having a pairof oppositely extending cylindrical extensions Ill and I2 adapted forbearing engagement with the bushing portions 52 and 62, respectively, ofthe side plates.

The rotor is adapted to be rotatably driven by a main drive shaft 14connected to the driving motor I2 by a suitable coupling connection I6.The rotor is spline-connected to the drive shaft I4, as best shown inFigs. 2, 3 and 4, the splined aperture of the rotor being sufficientlylarger than the shaft splined portion so that the rotor is looselycoupled with the drive shaft. In other words, the drive shaft servesmerely as a means for imparting rotation to the rotor, the path oftravel and bearing support for the rotor being determined by the bearingengagement between the rotor extensions 18 and I2 and the associatedbushing portions 52 and 62 of the side plates. By this means vibrationor slight irregularities in the alignment of the drive shaft 14 are nottransmitted to the rotor.

The outer end of the drive shaft 14 is journaled within a ball bearingstructure I8, Fig. 2, the outer race of which is press-fitted into thecentral bore 88 of the auxiliary housing body. A welch plug or the like82 provides a fluid-tight seal for the end of the bore 88. The oppositeend portion of the shaft 14 is journaled within a ball bearing structure84, the outer race of which is press-fitted into a bore 86 formedcentrally within the main housing body 20. As will be understood,suitable means such as a threaded nut 88 and split ring 98 may beemployed for holding the drive shaft and the associated bearings fromaxial displacement. The means for retaining the bearing 84 in positionincludes an end cap 92 bolted to the flange 28 of the main housing bodyby suitable means such as screws or studs 94. A rotary sealing mechanism96, the details of which form no part of the present invention, providesa liquid-tight seal for the inner end of the shaft I4, for preventingfluid from gravitating along the drive shaft surface through the centralbore of the end cap 92. The sealing mechanism is held from axialdisplacement between the bearing 84 and the end cap, and may be of anysuitable approved design and construction. The central chamber 98 of theend cap communicates with a drain passage I00 in the cap and a drainpassage I02 in the main housing body, the latter drain passagecommunicating with the main inlet channel 34, as shown. These drainconnections receive the seepage oil from the side plate bearings, aswill be presently described.

As shown in Figs. 4 and 6, the rotor 88 is provided with a plurality ofgenerally radially disposed slots I06 spaced uniformly along the rotorperiphery. While these slots are generally radially arranged, it will benoted that they are offset slightly from true radial positioning, asbest shown in Fig. 4. The slots are somewhat enlarged at their baseportions as indicated at I08, to provide a fissure-resisting slot end,and also to facilitate transmission of fluid across the rotor at thebase of the slots, as will presently appear. The slots are arranged toreceive a series of blades III), one of which is shown in perspectivedetail in Fig. 6A. As shown in Fig. 6A, the blade is generallyrectangular in shape except that it is preferably provided on itstrailing side with a pair of bevelled corner portions as indicated at II2 and H4. These bevelled portions facilitate the movements of theblades within the rotor slots, and also reduce the area of contactbetween the blades and their operating cam now to be described.

The blades are adapted for sliding contact with the inner cam surface II6 of a cam member I I8 press-fitted into the enlarged end bore I20 ofthe main housing body. The cam member is preferably provided at onepoint along its periphery with a notch or groove I22, Figs. 2 and 6,communicating with annular chambers I24 at the peripheries of the sideplates, and a drain line I26 in the housing body, to provide oildrainage from the side plate peripheries, if required.

The cam member H8 is also provided with a transverse opening or holeI28, Fig. 6, adapted to align with similar holes I30 and I32 in the sideplates and with holes I34 and I36 in the housing bodies so that alocating pin may be projected through the cam, side plate, and housingassembly so as to align and hold these parts in proper position relativeto each other,

The cam track II6 of the cam member is provided, as best shown in Fig.9, with a pair of circular surfaces I 38 of smaller diameter, a pair ofcircular surfaces I40 of larger diameter, and cam surfaces I42 formoving the blades IIIl inwardly and outwardly as they move along thesurface of the cam member. In accordance with the present invention thecam surfaces I42 are so shaped as to impart simple harmonic motion tothe blades for any given constant speed of rotation of the rotor. Thedevelopment of one of the cam surfaces I42 is'shown in enlarged detailin Fig. 10. It will be seen that the smaller circular surface I38extends for a distance of approximately along the cam quadrant, and thatthe circular surface I40 similarly extends along each quadrant for adistance of approximately 20 The cam surface I42 extends along theremaining of each quadrant, the development of this surface being such,as stated, as to impart simple harmonic motion to the blades in theirmovements outwardly and iii-- wardly of the rotor slots I06. By thismeans a minimum of shock is imparted to the blades in their movements,thus enabling the blades better to follow the contours of the cam memberto be controlled thereby. More particularly, in accordance with theprinciples of simple harmonic motion, the blades have their speeds ofmovement progressively increased as they leave one circular surface, forexamplethe surface I40, until they reach a maximum speed of movement atthe steepest central portion of the cam surface, as indicated at I44,whereupon the speed of movement is then progressively and uniformlydecreased until the blade reaches the outer circular surface I38.

To provide lubrication for the rotor, in its movements within thebushing portions 52 and 62 of the side plates, it will be noted that theexhaust side plate is provided on its outer face, remote from the rotor,with four grooves or channels I46, Figs. 3 and 6, communicating betweenthe ends of the ports 64 and 66, and four openings or holes I48, Figs.3, 5 and 6, drilled through the side plate flange. These holescommunicate with an annular channel i56 formed by suitably recessingcooperative annular portions of the side plate and rotor, this recess inthe exhaust side plate 58 being shown at I52 in Fig. 6. A similarannular channel I54 is formed by recessing cooperative annular portionsof the rotor and the inlet side plate, these recessed portions beingindicated at I56 and I58 on the rotor and inlet side plate in Fig. 6.Communication between the annular channels I50 and I is provided by theenlarged slot portions I98 of the rotor, whereby said channels I50 andI54 are continuously provided with the fluid being pumped, at exhaustpressure, from the exhaust ports 64 and 66 of the exhaust platestructure. From the annular channels I56 and I54 the oil being pumped,at exhaust pressure, may gravitate slowly between the rotating surfacesof the rotor and the bushings 52 and 62, whereby to lubricate and sealthese relatively moving surfaces. Such gravitating or seepage liquidfinds its way to the surface of the main drive shaft I4, whereupon itcan move to the chamber 98 and drain through the drain passages I06 andI62, previously referred to. The pressure fluid also is forced from thechannels I56 and I54 along the side plate flanges between the fiangesand the rotor to lubricate the bearing engagement between the sideplates and the rotor and blades. The pressure fluid in the passages I66also insures the proper lubrication of the blades within the rotorslots. The pressure fluid within the rotor passages I66 also aids inmaintaining the blades radially outwardly in engagement with the surfaceof the cam member.

In operation, as the rotor 68 is rotatably-driven "through its splinedconnection with the drive 75 the side plates. '33; thus maintaining'thebalshaft I4, in the direction indicated by the arrow in Fig. 4, the oilor other fluid being pumped will be withdrawn from the inlet channel 34,and from the inlet supply pipe I4, and propelled outwardly through thechannel 42 and exhaust outlet pipe I6, in proportion to the rotor speed.More particularly, as the rotor is driven, the blades H0 carried therebyare maintained in contact with the track surface II6 of the cam member'-II8, by the action of centrifugal force supplemented by the fluidpressure within the rotor passages I08, whereby to conduct and propelthe fluid from the inlet ports 54 and 56 "of the inletside plate 48 tothe outlet ports 64 and 66, respectively, of the outlet side plate 58.The positioning of the inlet ports '54 and 56 is indicated in Fig. 4-bydot and dash lines. It will be seen that the blades experience tworadial reciprocations within the rotor slots I66 for each revolution ofthe rotor, the blades moving radially outwardly as they pass the inletports upon enlargement of the pumping chamber to withdraw the fluid fromthe ports, and moving radially inwardly as they pass the outlet portsand as the pumping chamber is reduced to exhaust the fluid from thepumping chamber and outwardly through the exhaust ports and connections.As will be understood, Fig. '7, the rotor is sufficiently smaller thanthe smaller diameter of the cam member to permit its free rotation.

As hereinafter pointed out, the pump of the present invention is adaptedparticularly for the improved high pressure pumping of fluids, with highmechanical and volumetric efliciency, and with minimized wear. Theseresults are secured by providing proper and insured contact between theblades and the cam, and by providing very small clearance (on the orderof a few ten thousandths of an inch) between the rotor and the sideplates, between the bladesand the side plates, and between the bladesand the rotor slots; and by maintaining such contact and clearancesuniformly at all speeds of operation and at both high and low pumpingpressures. The shaping of the cam surface II6 of the cam member '8,which imparts simple harmonic motion to the blades, the "reduced area ofcontact between the blades and the cam provided by the blade bevels, and

the fact that the blades and cam are precluded from twisting ordistortion, even when subjected to high pumping pressures, combine toinsure and maintain proper and vibrationless fluid-tight contact betweenthe blades and the cam surface, to promote mechanical and volumetricefficiency and preclude wear. Similarly the maintenance of the blades,the rotor, and the side plates in proper position and against distortionduring high pressure-pumping permits the use of initial small clearancesbetween the parts, as stated, to promote and. maintain volumetricefficiency and preclude'wear orfriction drag. In this connection it isto be noted that the inlet and outlet channels '34 and 42 are bothannular, and are symmetrically disposed within the main and auxiliaryhousings coaxially with the rotor. By this means the relatively highpumping pressures produced in the outlet channel 42 do not tend todistort the auxiliary housing, in its relation to the mainhousing, butmerely applies 'a uniform'stress circumferentially of the auxiliaryhousing, and to the 'studs 24, whereby'to preserve and maintain auniform compression of the gasket 26 between the housings and a uniformspacing between the flanges 50 and of ance and positioning of the sideplates and the cam, and by causing the rotor to be at all times guidedin its movements by the side plate bushings, cocking or distortionbetween the rotor and the side plates, or between the blades and therotor, side plates or cam, is precluded.

The channels I50 and I54 between the rotor and the side plates aresimilarly annularly disposed coaxially of the rotor, so as to precludethe setting up of twisting or distortional forces.

It is to be noted that the principal housing functions are effected bythe main housing 20 which houses and supports the cam member, and alsoforms the principal housing and support for the rotor and the driveshaft.- The auxiliary housing 22 is in effect an auxiliary drive shaftand rotor support member, secured to and supported by the main housingin such a manner that the fluid pressures produced therein do notdistort or twist the main housing member, the auxiliary housing member,or the relationship therebetween.

The free splined connection between the drive shaft 14 and the rotorpermits the rotor movements to be accurately guided by the side platesand the bushing parts 52 and 62 of the side plates, any possiblemisalignment of the drive shaft or vibration thereof, due to high speedoperation (for example 1200 to 3600 R. P. M.), not being transmitted tothe rotor. The possibility of any such misalignment, however, isminimized by reason of the double bearing support for the shaft and thefact that the surfaces in the main and auxiliary housings for receivingthe side plate bushings and for receiving the bearing 84 and the bearing18 are all concentrically disposed and may be simultaneously machinedwith the main and auxiliary housings in assembled relation.

The inlet and outlet ports cooperating with the rotor blades areprovided in 90 spaced relation in separate side plates, the, inlet portsbeing provided in the inlet side plate 48, and the outlet ports beingprovided in the outlet side plate 58, as previously described. Thisporting arrangement provides a maximum surface contact area and barriersurface for the blades between the ports, reducing wear which in turnminimizes the possibility of leakage between the ports.

Also, it will be seen that the ports are oppositely diametricallydisposed in each plate, and that the inlet ports 36 and 38 and theoutlet ports 44 and 46 are similarly diametrically oppositely disposedwithin the main and auxiliary housings, further insuring the productionof symmetrical or balanced forces upon the parts in operation, topreclude twisting and distortion. Likewise, there is provided inwardlyof the inlet and exhaust ports an annular sealing portion excludinginlet pressure from the base of the rotor.

As has been previously pointed out, the simple harmonic motion impartedto the blades by the cam surface I I6 insures vibrationless maintainedcontact between the blades and the cam with resultant pumpingefiiciency, as well as a minimum of shock and wear to the parts inoperation. Moreover, referring particularly to Fig. 4, it will be seenthat the cam surfaces I42 are substantially commensurate in length withthe inlet and outlet ports of the side plates, so that the blades willundergo their reciprocative movements while aligned with the ports, andwill be maintained in a substantially stationary position within therotor slots as they enter and leave their alignment withthe port ends;thus minimizing shock and facilitating the cooperative engagement of theparts without the possibility that the blades will dig into the walls ofthe side plate flanges at the ends of the ports. To further minimizeshock and facilitate noiseless and vibrationless operation, it will beseen that the approach ends of the side plate outlet ports 64 and 66 areprovided with notches 60 of gradually decreasing depth, whereby toprovide feathered port ends for establishing gradual pressurecommunication be-- tween the pumping chambers and the outlet ports asthe blades engage the ports.

By reason of the nature of the structure provided, the blade pump of thepresent invention may be satisfactorily employed for pumping liquid suchas oil at relatively high pumping pressures, for example 2000 pounds persquare inch, more than twice as great as the pressures employed inconnection with conventional blade pumps.

It is obvious that various changes may be made in the specificembodiment set forth without departing from the spirit of the invention.The invention is accordingly not to be limited to the precise embodimentshown and described, but only as indicated in the following claims.

The invention is hereby claimed as follows:

1. A rotary high pressure blade pump comprising a housing, composed of apair of complementary housing parts, a rotor drive shaft, a rotorincluding oppositely projecting cylindrical portions embracing the driveshaft and an intermediate flange portion disposed between said housingparts and in which blade' slots are provided, blades reciprocable insaid slots and operable to propel fluid, each of said housing partshaving an annular channel around and spaced from the drive shaft andforming, respectively, inlet and exhaust passages for fluid, a singlepair of diametrically opposed inlet ports in one of said housing partscommunicating with the inlet passage therein and arranged to transmitthe full flow of inlet fluid to the rotor, a single pair ofdiametrically opposed exhaust ports in the other housing partcommunicating with the exhaust passage therein to transmit the full flowof exhaust fluid from the rotor, .means providing a pair of side platesdisposed in said housing on opposite sides of said rotor, each of saidside plates including a central cylindrical hub portion projectingtherefrom to embrace a cylindrical portion of the rotor and a flangeportion disposed between the adjacent side of the rotor flange and theadjacent housing part, the flange portions of said side plates includinginlet and. exhaust ports registering, respectively, with the adjacentinlet and exhaust ports in said housing parts, each port of each pair ofinlet and exhaust ports being disposed in the vicinity of the outerperiphery of the rotor and the blades carried thereby and of limitedcircumferential extent to provide between adjacent ends of the ports ofeach pair a continuous planar barrier surface of greater circumferentia]extent than the extent of said ports, said barrier surface being inplanar contact with the rotor between the said ports and includin acontinuous annular sealing portion disposed in-- wardly of said ports incontact with the rotor and of such radial extent as to exclude inletfluid pressure from the inner ends of the blade slots and from thevicinity of the cylindrical portions of the rotor and resisting leakageof fluid tracked by adjacent edges of the rotor blades, the said inletports being disposed in quadrature relative to the exhaust ports withadjacent ends of the inlet and exhaust ports from one another andrelative to the spacing of the rotor blades such that at least one rotorblade is always presented between adjacent ends of inlet and exhaustports, and a cam member defining the rotor chamber and including anopposed pair of substantially circular arcs of substantially thediameter of the rotor and an opposed intermediate pair of substantiallycircular arcs of greater diametral spacing than the diameter of therotor, the said arcs tangentially by cam surfaces shaped to impartsubstantially uniform acceleration and deceleration to the rotor bladesupon rotation of the rotor at constant speed and presenting with saidarcs 5 a continuous unbroken inner surface for engagement with the rotorblades.

2. A rotary high pressure blade pump as claimed in claim 1, wherein thecam surfaces are shaped to impart simple harmonic motion to the rotorblades upon rotation of the rotor at constant speed.

3. A rotary high pressure blade pump as claimed in claim 1, wherein thecam surfaces each have a length substantially commensurate with thelengths of the inlet and exhaust ports.

4. A rotary high pressure blade pump as claimed in claim 1, whereinthere is provided at the base of the rotor and on opposite sides thereofa pair of annular L-shaped lubrication and pressure channels, the radialportions of the channels being disposed between the flange of the rotorand adjacent flange portions of said side plates and in communicationwith one another through the base of the rotor slots to direct exhaustfluid behind the blades, and the axial portions of the channels beingdisposed between adspaced circumferentially V being joined jacent hubportions of the side plates and cylindrical portions of the rotor, andwherein passageways are provided between one of saidjehannels and theexhaust ports for the transmission of exhaust fluid to the channels. ,1

- ERNEST J. SVENSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

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